what is the highest degree you can do and whats the lowest you can do? ( in the united kingdom)?

Answer 1

The Highest officially is a PhD.

You can do post-doctorate research (and still be classed as a student for tax purposes), be made a professor, a fellow, and eventually a Chair at a University. So Chair is the highest title. Or perhaps Chancellor, but that's more of a political appointment.

The lowest degree is an HND. Anything lower is equivalent to A levels really.